1. Field of the Invention
The present invention is directed to a retaining pin assembly for a lifting system. In particular, the present invention is directed to a retaining pin assembly wherein a retaining pin and a retaining ring maintain a lock arm or bail arm in place in a closed position when in use and wherein the retaining pin may be partially retracted so that the retaining ring resides in a recess in the lock arm or bail arm.
2. Prior Art
In a number of lifting or hoisting devices, such as tubing blocks, a hook or multiple hooks are utilized for lifting. An elevator link, wire line, chain or other load is installed in the hook in order to support a load. When in use, the hook is kept in a closed position by a lock arm, a bail arm or a latch. The lock arm is kept in the closed position by a retaining pin or pins. In order to disassemble the lifting device, the lock arm, bail arm or latch is unfastened by retracting the retaining pin or pins.
In a number of applications, a retaining pin passes through the lock arm and a hook cam and locks or secures the lock arm in place. A retaining pin also passes through the lock arm and a hook prong. The pins may have a threaded connection to the lock arm or may be held by a cotter pin.
The lock arms are engaged for use and disengaged in the field under a wide variety of conditions. It would be advantageous to be able to retract the retaining pin or pins from the lock arm without removing the retaining pin or pins from the lifting assembly.
Accordingly, it is a principal object and purpose of the present invention to provide a retaining pin assembly for a lifting system wherein a retaining pin will pass through the lock arm when in a use position and wherein the retaining pin may be retracted without disengaging the retaining pin from the lock arm.
It is a further object and purpose of the present invention to provide a retaining pin assembly having one or more grooves or slots in a retaining pin shaft to hold a retaining ring thereon.
It is a further object and purpose of the present invention to provide a retaining pin assembly with a retaining ring wherein the retaining ring may be withdrawn into a recess in a lock arm during assembly and disassembly.